Vibraphone.



1. L GALBRAITH.,

VIBRAPHONE.

. APPLICATION FILED 05c. m. 1916. 1,246,584. Batented Nov. 13, 1917.

ISAAC J. GALBRAITI-I, or PITTSBURGH, PENNSYLVANIA.

VIBRAPHONE Specification of LettersPatent.

Patented Nov. 13, 1917.

Application filed December 14:, 1916. Serial No. 136,915.

To all whom it may concern:

Be it known that I, ISAAC J. GALBRAITH, aresident ofPittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Vibraphones, of which the following is a specification.

This invention relates to a mouthpiece, or transmitter, for telephones The objects of the invention are to provide a cap for the ordinary telephone transmitter mouthpiece,

including means to hold a disinfectant, andv having an element to amplify the vibrations of the voice, and so to secure greater clearness and carrying power of speech.

The advantages of the invention will appear more in detail throughout the following specification.

The drawings illustrate an embodiment of the invention, wherein Figure 1 shows a plan view of the device in position on the telephone as shown in detail in Fig. a; Fig. 2 is an under plan view of one of the members inside the cap; Fig. 3 is a plan View of the cap itself; Fig. a is a central section through the device applied to a telephone mouthpiece; and Fig. 5 shows an expansion ring locking member.

My invention comprises a cap 1, preferably stamped from sheet metal, having a central opening 2, and having its outer edge turned inward to form a flange or skirt portion 3, which has an inner terminal annular bead 4.. A housing 5 made of screen wire is adapted to just fit into the central opening 2, and to be retained on the inside of the cap by a flared terminal flange 6. Another piece of wire screen 7 is attached to an'annular paper disk 8 which is adapted to fit into the cap, and to retain thehousing 5 in position between the cap and disk, the screen 7 closing the housing 5, and so forming a perforated receptacle, which is ordinarily used for containing some form of disinfectant, as more fully described below. On the inside of the screen member 7, at the central point of the disk 8, a spiral coil spring 9, tapering to a point, and preferably made of very fine copper wire, is attached. This spring is formed of a great number of turns of small wire, close together, of small diameter, and is attached to the wire gauze merely by one end of the spring, so that it is held in a position in which it is free to vibrate at the least disturbance.

The device is assembled as follows The the vibrating spring at the center of the opening through the housing 5. A paper washer 10, which ordinarily isin the form of an annular ring, such as might be illustrated by Fig. 3, is forced into position around the flared portion of the telephone mouthpiece 11, and then a metal expansion ring 12 is compressed and forced into the position shown in Fig. 4:, being retained by the head a on the inner edge of the skirt 8. This securely locks the washer 10 in position, and holds the cap firmly on the telephone mouthpiece.

A disinfectant, in the form of some absorbent body, carrying a few drops of a suitable liquid, is kept in the screened housing 5, but occupies only a small portion of the space provided, so as not to obstruct the passage of sound waves through the opening. This may be renewed from time to time by adding liquid to the absorbent medium.

The operation and use of the device is as follows: When. it is assembled in the position shown in Fig. 4: on the ordinary telephone mouthpiece, the vibrations of a speakers voice pass freely through the wire screen and cause the fine coil spring 9 to vibrate in the frequency of the sound wave. In other words, the spring is set in vibration, and accords with the vibrations of the voice, but persists longer than the sound waves, and so acts as an amplifier of the sound, and secures a more distinct, and more prolonged transmission of these waves to the telephone diaphragm, which by a varying electrical contact causes the transmission of sound waves, as is well known in the telephone art.

It has been found in actual practice that this device will greatly in crease the efliciency of the telephone, and allowing the speaker to use a much lower tone of voice, and secure clearness in cases where transmitting conditions are poor. In addition, it furnishes a ready means for the carrying of an anti septic at the exposed point of a telephone.

I claim A perforated cap for a telephone mouthpiece carrying a vibratory member extending inside the telephone mouthpiece.

2. A cap for use with a telephone mouthpiece, comprising a wire screen central member, and a coiled spring attached thereto and positioned inside the telephone mouthiece. p 3. In combination with atelephone mouthpiece, a cap adapted to be fixed on the mouthpiece and comprising a perforated central member having a coiled vibration spring attached to the central point thereof and extending into the telephone mouthiece. P 4. In combination with atelephonemouthpiece, a cap adapted to be fastened thereon and having a central perforated housing chamber adapted to retain a disinfectant,

and a coiled spring attached to the central portion of the perforated housing and positioned inside the mouthpiece.

spring carried by the cap and positioned inside the mouthpiece.

In testimony whereof, I have hereunto set my hand.

ISAAC J. GALBRAITH.

Witnesses A. OsBoURNE, HRY. REUTER.

Copies 01 this patent may be obtained for five cents each, by addressing the "Commissioner of Patents.

' Washington, D. 0. 

